Ecologia de lianas em fragmentos de florestas ombrófila e estacional no domínio atlântico de Pernambuco

Abstract

Lianas are found with greater richness, diversity and abundance in tropical forests and represent an important part of the structure and total diversity of these forests. However, it is still the least studied component, which creates great lacunae about knowledge about floristic-structural, regenerative aspects and factors influencing lianas in the various vegetation formations. The objective of this study was to characterize and compare the floristic composition and structure of lianas, to evaluate possible differences in the taxonomic diversity between the two forests and to verify if the forest type and the local variables (canopy opening, soil fertility and density) influence the regeneration strategy of lianas. The study was developed in two fragments of Atlantic forest, one of which is ombrophylous and the other is seasonal forest. All lianas with height ≥ 1 m were sampled in 50 plots of 20 X 20 m (2 ha) in each type of forest. The diversity among the forests was analyzed by the effective number of species (Hill Numbers). Differences in composition were determined by non-metric multidimensional scaling (NMDS), floristic similarity analysis (ANOSIM) and by the similarity percentage procedure (SIMPER). Differences in soil fertility, canopy opening and tree density between the two forests were analyzed by the Wilcoxon test. To verify if the abundance, richness or diversity of genets and ramets differ with the forest type, generalized linear models (GLM) were constructed. Analyzes of diversity and floristic composition indicated the existence of significant differences between the forests: while the ombrophylous forest had greater species richness, the semidecidual forest had greater abundance and diversity of lianas. The dissimilarity among forest types was 94%. These results indicate that although both forests occur in the same morphoclimatic domain, the diversity of lianas is significantly different between an ombrophylous and a semidecidual forest. The forests presented differences as to the opening of the canopy, soil fertility and density of trees. The forests showed differences in the richness, diversity and abundance of genets and ramets, showing that the environmental conditions are important factors for the definition of liana regeneration strategy.